Assistant Professor of Environmental Engineering
The Pennsylvania State University
As the most abundant biopolymer on earth, cellulose is a significant renewable resource that has the potential to be converted to useful energy carriers and satisfy a fraction of our energy needs. This talk will present our work on the microbial conversion of cellulose to hydrogen and electricity. Certain microbes can hydrolyze cellulose and ferment the glucose monomers to hydrogen and various soluble products. We characterized the hydrogen yields and production rates from six mesophilic, cellulolytic clostridia species, and found that Clostridium cellulolyticum and Clostridium populeti catalyzed the highest hydrogen yields from cellulose and achieved 25–100% higher hydrogen production rates than the other species. We then coupled the cellulose hydrolysis and fermentation by C. cellulolyticum with anode reduction by Geobacter sulfurreducens in a microbial fuel cell for the production of cellulose-derived electricity. Neither of these bacteria could independently produce electricity from cellulose, but their combined phenotypes successfully catalyzed this conversion.